Firearm



March 12; 1946. A. GAL 2,396,564

FIREARM Filed Jan. 30, 1939 Fig. 1

INVENTOR ALLESANDRO GA'L 6v 4 6 ATTYS.

Patented Mar. 12, 1946 FIREARM Alessandro Gal, Oltrona a1 Lago,Gavirate, Varese, Italy; vested in the Alien Property CustodianApplication January 30, 1939, Serial No. 253,661

In Italy February 5, 1938 2 Claims.

This invention relates to breech closing means for firearms and moreparticularly for automatic and semi-automatic firearms and it comprisesa breech closing mechanism in which the breech bolt cooperates with aslider mounted to move longitudinally with respect thereto, said slidercooperating with means to lock said breech bolt in breech closingposition.

An entirely reliable and self-locking closing mechanism is obtained inaccordance with this invention by means of parts to which a translatoryrectilinear movement only is imparted and with the aid of fiat slopingsurfaces which may be easily machined with full precision as required.

An embodiment of this invention is illustrated by way of example on theannexed drawing and Figure 1 is a longitudinal fragmentary section onthe barrel axis of an arm equipped with the means of this invention thebreech bolt being in closed position.

Fig. 2 is a longitudinal section similar to Fig. 1 with the breech boltin open position;

Fig. 3 is a longitudinal section, on an enlarged scale, through thefirearm of Fig. 1 taken along the line 3-3 thereof;

Fig. 4 is a cross-section, also on an enlarged scale, through thefirearm of Fig. 1 taken along the line 4-4 thereof and looking in thedirection of the'arrows;

Fig. 5 is a side view of a separate locking member and Fig. 6 is a topplan view of the locking member shown in Fig. 5.

Fig. 7 is a perspective view of the locking member oi'Fig. 5.

In Figures 1 and2, l denotes the firearm barrel and 2 denotes thereceiver which has grooves 8 in internal faces of opposite wallsthereof, said grooves being connected with sloping seats I0 whichdiverge transversely to the respective grooves 8 connected therewith andare inclined to the direction in which said groove extends.

An elongated member 26 which serves as a breech bolt is mounted toreciprocate in the chamber confined within the receiver 2 and saidenters; said spring abuts on a plug 34 closingthe receiver 2 at its rearend.

The bolt 26 has a transverse slot 35 bounded by side portions 26'intermediate its extension 30 and its spring socket 3| and a slider 32is mounted to reciprocate along said bolt 26 within the slot 35 thereof.

The slider 32 has upper and lower extensions 33 adapted to embrace thebolt central extension 30 and to abut on the transverse faces 29 of thebolt 26.

Looking shoes 9 are provided for cooperation with the bolt 26, theslider 32 and the receiver 2, and each of said shoes includes a mainbody (Figs. 5, 6 and 7) having transverse faces 36, 31 at itslongitudinal ends and a uiding lug II adapted to enter a cooperatingreceiver groove 8. On each side the locking shoe 9 provides a noseconfined by longitudinally extending faces I2, I 2 and by sloping endfaces I3, I3, the faces l2, I2 being intended to slide along cooperatingsurfaces of the receiver 2 and slider 32 while the sloping faces I3, I3have an inclination registering with that of the side surfaces of thesloping seats Ill.

The sloping seats H], as shown in Figs. 2 and 3 extend downwardly beyondthe inner levels of the grooves 8, so that when the shoes 9 arrive inlocking position adjacent the openings of the sloping seats III, theinclined faces I3, I3 engage the said seats at said openings and theshoes 9 move outwardly into the chambers or spaces provided between theslider 32 and the bolt lugs 28, and thus into the locking position shownin Fig. 1, in which the faces I2, I2 of the shoes lie in the seats I0.

The respective positions of the bolt 26, slider 32 and locking shoes9are shown in Figures 1 and 2. When the bolt 26 is in its open position(Fig, 2) said locking shoes 9 are positioned in the space intermediatethe transverse faces 29 of the bolt 26 and the opposite end faces of theextensions 33 of the slider 32 which are in their position at maximumpermissible distance withrespect to the bolt extension 30.

On the contrary at the time the locking shoes 9 are .within the slopingseats I9 (Fig. 1) each of them abuts frontally against a face 29 of thebolt 26 and the opposite face of the cooperating seat l0 and it restsagainst the side face of the adjacent extension 33 of the slider 32which projects over the bolt extension 30; the breech closing parts ofthe firearm then are in their locked position.

The striker includes a stem [4 having an end pin l4 said stem i4 isconnected with the slider 32 and extends throughout a central bore ofthe bolt 26 where a spring I5 is located, this spring abutting on aflange M" of the stem M at one of its ends and on a sleeve 38 fast inthe bolt 26 at its opposite end.

The spring I5 is thus operative both to drive the striker forward and tomove the slider 32 into its advanced position which corresponds with the'bolt locked position.

The slider 32 is provided with a transverse hold the bolt 26 in openposition and the striker spring cocked, said sear |9 being adapted to bereleased by means of a wedge trigger 29 I a firinggas outlet 25 from thebarrel opens.

The bolt 26 has in turn on the path of the finger I8 a similar finger I8which is engaged by the finger IS in its recoil stroke.

In the position of the parts shown in Fig. 1 the firearm receiver 2 isclosed by the front face of the rod 21 of the bolt 26 located againstthe rear end of the bore of the barrel I Ihe breech bolt 26 is in turnlocked. by the locking shoes 9 which abut on the transverse faces 29thereof and are in turn engaged within the seats ll] of the receiver 2said shoes 9 being restricted from coming out therefrom due to theirabutment against the sides of the extensions 33 of the slider 32.

The breech is thus closed in a fully efiicient manner and its closing isthe more reliable the greater the rearward thrust exerted on the bolt21, 26 because said thrust is imparted to locking shoes 9 which are thuswedged intermediate the faces of the inclined seats l0 and the sliderextensions 33.

In fact the force the cartridge base transmits to the bolt, 26 and toshoes 9 at the time a sho't is fired, is resolved into two componentsone of which acts on the receiver 2 and the other on the slider 32 in adirection perpendicular to the barrel axis, the second named componentshaving the same line of action and opposed directions iii-respect of thetwo shoes '9 so that no torque is imparted to the receiver.

For opening the bolt 26, 21 the slider 32 is moved back; in thedescribed construction such a back displacement is caused by thepressure imparted by the rod 2| which is moved back, immediately after ashot fired, by the action of the firing gases issuing from the barrel Ithrough the duct 25 and operative on the bottom of the sleeve 23 at thetime the bullet has moved past the orifice of said duct 25 in the fixedpiston 24.

At the time a shot is fired the rod 2| thus recoils under the action ofthe shot firing gases and imparts a blow on the finger I8; the slider 32is thus caused to recoil against the action of the striker spring l5whilst the bolt 26 at first remains stationary due to the longitudinalgap intermediate said slider 32 and the bolt '26.

In' this operation due to the movement of the slider 32 along the boltslot 35 the side abutments provided by the slider extensions 33 forthelocking shoes tare removed and. said shoes 9 slide along the slopingseats l0 under the action of bolt faces 29 on the shoe faces 31 due tofiring gas pressure on the bolt 26, 21 and to the recoil action of theslider 32 on said bolt, said locking shoes thus finally taking aposition in contact with the bolt extensions 30 (Fig. 2)

Then the bolt. 26 recoils against the spring 3 with slider 32 under theaction of rod 2| and slider 32 to reach its positionin which the sliderfinger I8 is engaged behind the sear |9 (Fig. 2).

-To fire a shot a pressure is applied to the push button 39 to shift thetrigger 29 and to remove finger |8 intended to cooperate with a sear 19to the 'sear IS, the bolt 26 thus moving forward with the slider .32under the action of the spring 3; at the time the bolt 26 stops in itsforward end position theslide'r 32 further advances under the action ofthe striker spring l5 and the front faces of the extensions 33 thereofdrive the shoes 9 in front thereto said shoes being finally caused toenter the sloping seats l0 connected with the receiver grooves 8.

The slider 32 may thusreach its most advanced position to drive thestriker pin i4, I4 against the cap of a fresh cartridge fed in thebarrel bore only after said shoes 9 have entirely released the path ofthe extensions 33- of the slider 32 and Accordingly the shot isfired'only at the time the bolt is fully closed and looked that is whenthe bolt 26 is engaged bythe shoes 9 which in turn abut against thesidesof the slider extensions39. j

The breech is thus fully closed at the time a shot is fired and acartridge-may be struck only after the bolt has been locked in closedposition, all the requirements inherent to a regular and safe operationof an automatic firearm being thus satisfied. V I

g The above described result is obtained without parts operating withrotarymotion and'accordingly no member of the mechanism issubject toharmful torsional actions.

Further due to the restricted mass of the slider 32 any liability torebound actions is removed. 7

While in the preferred example shown in' the drawingtwo locking shoesare provided, it is obvious that any other numberof such locking shoesmaybe used. If more th'an two locking shoes are provided they should be.conveniently arranged in a symmetrical positionwith respect to thelongitudinal axis of the barrel, thusavoiding unbalanced transversestrains. i

What I claim as my invention and desire to secure by United StatesLetters Patent 1. In a firearm,'a receiver and a barrel extending fromsaid receiver, an-elongated breech bolt mounted to reciprocate in saidreceiver, said bolt having a slot, intermediate its ends and formed witha rearwardly opening socket, means for urging said bolt in a position toclose said barrel, said means including a spring, one end of whichspring bears against said receiver and the other end against said boltin said socket, said receiver having in the internal surface of itswalla longitudinal guideway having an extension in a direction inclinedto the reciprocatory path of. said bolt, a slider mounted in saidreceiver and in said slot of said bolt, to reciprocate with respect tosaid bolt, bolt locking means wholly independent of said bolt andsliderfland mounted to movejin said receiver guideway alongthe pathofsaid bolt in said receiver, means on said lockingfnieans arranged toenter saidinclined extension of said guideway, and when so'positionedgto hold said locking means engaged with said slider and saidbolt to lock said bolt in its barrel closing position.

means urging said slider forwardly into a position adjacent to saidinclined extension to move said locking means forwardly and thenoutwardly into said inclined extension and finally to hold said lockingmeans in said inclined extension in bolt locking relationship, and meansoperated by a shot being fired for shifting said slider and removing itfrom looking position for the release of said bolt locking means.

2. In a firearm, a receiver and a barrel extending from said receiver,an elongated breech bolt mounted to reciprocate in said receiver, saidbolt having a slot intermediate its ends and an axial bore in itsforward end portion, and formed with a rearwardly opening socket, meansfor urging said bolt in a position to closed said barrel, said meansincluding a spring, one end of which spring bears against said receiverand the other end against said bolt in said socket, said receiver havingin the internal surface of its wall a longitudinal guideway having anextension in a direction inclined to the reciprocatory path of saidbolt, a slider mounted in said receiver and in said slot of said bolt toreciprocate with respect to said bolt, a firing pin connected with saidslider and extending through said bore of said bolt, bolt locking meanswholly independent of said bolt and slider and mounted to move in saidreceiver guideway along the path of said bolt in said receiver, slopinglug on said locking means arranged to enter said inclined extension ofsaid guideway and when engaged therein to hold said locking meansengaged with said slider and said bolt to lock said bolt in its barrelclosing position, means urging said slider forwardly into a positionadjacent said inclined extension to move said locking means forwardlyand then outward- 1y into said inclined extension and finally to holdsaid locking means in said inclined extension in bolt lockingrelationship, and means operated by a shot being fired for shifting saidslider and removing it from looking position for the release of saidbolt locking means.

ALESSANDRO GAL.

